Lifting-jack



C. A. JONES.

LIFTING JACK. APPLICATION FILED 020.29, 1919.

Patented July 12', 1921.

2 SHEETS-SHEET I.

C. A. JONES.

LIFTING JACK.

APPLICATION FILED 020.29, 1919. 1,384,322. Patented y 1 1921'.

2 SHEETS-SHEET 2.

CHARLES ALLAN JONES, or s-rioucnsrnnnnernnn.

marine-anon.

Application filed December 29,1919. Serial No. 348,068.

T 0 all whom it may concern: 1

Be it known that I, CHARLES ALLAN JONES, a subject of the Kingdom of Great Britain,

residing at Bohanam House, Gloucester, in

the county of Gloucester, England, retired manufacturer, have invented certain new and useful Improvements in or Relating to L ftmgJacks, of which the followlng 1s a specification.

This invention comprises certain improvements in or relating to lifting jacks, particularly of the type used for raising motor cars, but applicable for other purposes.

According to the present invention, the moving jaw of the ask is adapted to be elevated by a progressive process, as for instance by virtue of a pawl and rack action and the support for this moving jaw consists of two pivotally or hingedly connected legs one of which is rigid and the other has an independent articulation or pivotal connection along its length to so form'a toggle leg which is capable of being displaced or broken for depositing the load on the ground when necessary. The toggle is during the elevating process adapted to assume a position beyond its dead center, whereby the rigid leg assumes its more upright or supporting condition during the raising of the moving jaw. Vl hen it is desired to lower the car, provision is incorporated for dis placing the toggle across its dead center, as a. result of which that lee of the base frame which is constituted by the toggle becomes.

effectively shorter, thus increasing the in clination of the rigid leg and thereby reducing the eifective height of the jack. Both legs may be pivotally mounted on a suitable shoe base and a spring or springs may be incorporated for preventing the inadvertent displacement of the toggle as hereinafter more particularly described.

In order that this invention may be clearly understood and readily carried into practice, reference may be had to the appended explanatory sheet of drawings, upon which Figure 1 is an elevation of a lifting jack constructed according to the present inven tion in position or readiness for raising an automobile or other load.

Fig. 2 is a plan view of the lifting jack illustrated in Fig. 1.

Fig. 3 is an elevation of- .the jack illustrating the one arm being broken or collapsed for depositing the load on the ground, and

Specification or Letters Patent. Patented J 1y 12, 1921.;

I Fig. 1 shows the jack in the collapsed condition after having deposited the load.

In a convenient embodiment of the present invention, the jackbody comprises. a rigid leg 1, in the upper. part 2 of which the lift-' ing bar 3 of the jack is adapted to have a sliding movement. A second leg 4 converging upwardly in relation to said first-n1entioned leg is pivoted to the latter at the'top,

or upper part 2. Said second leg 4 has an if desired, togive a three-point supportto the jack; Pivoted to the rigid 'leg 1 is an operating lever 9 The short arm or exten-' sion 10 of this lever extends inwardly and carries a spring-controlled pawl 11 which is adapted to engage with a rack 12 upon the lifting bar 3. By oscillating the lever] 9 the lifting bar 3 is thus elevated. Pivoted slightly below or co-axially with the articulation 5- in the toggle is or are a link orlmks 13, which link or links extend in an upwardly inclined direction across the rigld leg 1. Said link or links are in turn pivoted to a second link or links 14 which incline slightly downwardly and are in turn pivoted to the top 2 of the rigid leg 1. By depressing the axis 15 at which these links or pairs of links are articulated together, the lifting bar leg 1. is broken, with the result that the inclination of the fixed leg 1 and of the lift ing bar 3 is increased to thereby reduce the effective heightof the jack, and so deposit the load upon the ground surface. 1 It will be noted in this action that the lpad is deposited after following an arc-shaped path having for its center the base of the fixed leg 1. This lateral. displacement of the load has the advantage that the jack may be utilized to effect a traversingproeess acoordingto which the load is deposited in a position removed from that from which it has been raised.

Pivoted to the arm or extension 10 operated by the lever 9 outwardly of its axis of oscillation is an upwardly extending hook 16 which is adapted to be engaged with the axis 15 of articulation between the links 13, 14, above described so that the operating lever 9 may then be depressed to break the toggle leg 4. This hook 6 which is carried by the operating lever 9 may be couple'd by a coiled spring 17 to the pawl 11 by which the lifting bar 3 is elevated so that when said hook 16 is engaged with theaxis of articulation 15 of the links for the purpose of breaking the toggle leg 4 the pawl 11 is automatically disengaged from the rack 12 (Fig. 3).

A spring-controlled pivoted detent 18 is provided at the top of the rigid leg to engage with the rack 12 of the lifting-bar 3, this detent is adapted to be released, as for instance by hand.

In the present arrangement, in the depositing action there is no variation in the foot base dimension of the jack on account of the legs 1 and 4 being pivotally connected to the rigid shoe base 6. (Fig. 4.)

A helical or other spring or resilient member 19 is incorporated between the toggle leg 4 and the upper part 2 of the rigid leg 1 in such a manner as to normally retain the toggle leg 4 in the straightened or unbroken condition and prevent the inadvertent collapsing of the leg 4 when the load is being applied. The resistance of this spring 19 is easily overcome in the collapsing or depositing operation with the handle 9 and hook member 16 as hereinbefore described.

Means may be provided for detachably connecting the handle 9 to the jack. To this end the arm or extension 10 pivotally connected to the leg 1 is provided with a small housing or compartment 20 (Fig. 1) having internally inclined faces 21, and the handle or lever 9 may be provided with a pivotally mounted pawl 22. In order to connect the lever 9 with the extension or arm 10 on the jack, the extremity of the said lever is thrust into the housing 20 so that the pawl 22 falls automatically and prevents separation ofthe parts 9 and 10. The jack can then be pushed or pulled beneath the automobile for adjustment. When it is desired to remove the handle 9 from the part 10, these two parts together portion of the rigid leg and having ratchet teeth, a second leg having its upper end pivotally connected to the rigid leg, its lower end pivotally connected to the base and provided with an articulation at a point intermediate its ends, a lever pivotally connected to the rigid leg, a pawl mounted on the lever and'arranged to engage the ratchet teeth of the lifting bar, and means, operable by said lever to bend or straighten the second leg.

2. In a lifting jack, a leg mounted for rocking movement and carrying a lifting element, a bendable leg also mounted for rocking movement and connected to the firstnamed leg, and means to bend or straighten 7 said bendable leg.

3. In a lifting jack, a base, a rigid leg pivotally connected at its lower end to the base, a lifting bar slidable vertically in the upper portion of the rigid leg and having ratchet teeth, a second leg having its upper end pivotally connected to the rigid leg, its lower end pivotally connected to the base and provided withan articulation at a point intermediate its ends, a lever pivotally connected to the rigid leg, a pawl mounted on the lever and arranged to engage the ratchet teeth of the lifting bar, links pivotally connected together and respectively pivotally connected to said legs, and means to connect said lever to said links.

In witness whereof I have hereunto set my hand.

CHARLES ALLAN JONES. 

